Electric switch



May 8, 1928. 1,669,106

J. F. TRlTLE ELECTRIC SWITCH Filed'Dec. 6. 1924 Invefinom John F. Tritle;

His Attornes- Patented May 8, 1928.

UNITED STATES PATENT OFFICE.

JOHN B. TRI'ILE, OF SCHENECTADY, NEW YORK, ASSIGNOR T0 GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTRIC SWITCH.

Application filed December 6, 1924. Serial No. 754,397.

My invention is directed to im rovements in electric switches of the trip ree type; that is, a type of switch which is arranged to automatically open upon the occurrence of an overload and which cannot be held closed by the means provided for closin the switch during an overload in the contro led circuit.

The present invention is a modification of the electric switch of this general type which is broadly claimed in my Patent No. 1,560,440, dated Nov. 3, 1925. The arrangement of the present application has features of advantage in the construction and arrangement of the switch, as will be pointed out particularly hereinafter.

For an understanding of, the invention reference is had to the accompanying drawing, wherein Fig. 1 is a diagrammatic re resentation of the various parts of the switch when the switch is in the open position. Fig. 2 is a similar very simple diagram showin the relative positions of the parts after t e completion of the initial movement of the means provided for effecting the closing of the switch, and Fig. 3 is a similar very simple diagram showing the relative position of the parts when the operating means for elfecting the closing of the main switch contacts has been released and the contacts have been permitted to close in accordance with a bias set up during the initial closing movement of the switch.

Referring to Fig. 1, the electric switch is shown as having two main independently movable contacts 10 and 11. Each of these contacts is mounted for movement, the contact 10 being mounted on the arm 12 which is pivoted at 13 and the contact 11 being supported by pins 14 and'15 which cooperate with slots 16 and 17 re ectively, so as to eflect a tilting movement and a longitudinal movement of the contact 11 durlng the interval of closing the switch. The contact 11 is normally biased into the. tilted position as shown in Fig. 1 by means of the spring 18 which holds this contact into enga ement with the pins 14 and 15 at the right and ends of the slots 16 and 17. The contact 11 is therefore biased toward the contact 10 by means of the spring 18, and

the contact 10 is biased away from the contact 11 by means of gravity and spring S. The arm 12 also carries the armature 19 of a holding electromagnet, the armature 19 cooperating with the poles of the magnetic structure 20 which is provided with a holding winding 21. The flux of the holding magnet is under the control of a bucking bar 22 which is disposed in the air gap between the poles of the magnetic structure 20 and is arranged so as to shift the flux of the holding magnet away from the armature 19 in accordance with the current in the circuit controlled by the main contacts 10 and 11. This arrangement whereby the flux of the holding magnet is under the control of the current in the controlled circuit is covered in my prior Reissue Patent No. 15,441, dated August 29, 1922.

The arm 12 carrying the contact 10 is moved into the closed position for the contact 10 so as to be magnetically held by the magnetic attraction between the magnetic structure 20 and the armature 19, by means of the operating member 23 which is pivoted at 13. This operating member is provided with a handle 24 so as to be manually operated, and is also provided with an electromagnet 25 so as to be electromagnetically operated if desired, under the control of the push button 26. As shown, the 0 erating member 23 is in the form of a ell crank lever, the upper arm of which cooperates with the arm 12, so as to move this arm to a position such that the contact 10 is in its closed position and the armature 19 is in a position to be held by the holding ma et. The arm is also provided with a post 2 of insulating material which is arranged to engage the main contact 11 and move this contact away from the contact 10 against. the action of the spring 18 during the initial closing movement of the switch.

As thus constructed and arranged, the operation of the invention is as follows:

With the various parts of the switch in their respective positions shown in Fig. 1, in order to close the switch, the pilot switch 28 will first be closed so as to energize the coil 21 of the holding electromagnet. Let it be desired to control the closing of the switch from a distance-the push button 26 will therefore be closed to energize the o erating electromagnet 25 and rotate the bel crank crating member 23 clockwise about the pivot 13, thus carrying the arm 12 into the position shown in Fig. 2 in which this arm is magnetically held y the holding electroma et and in which the main contact 10 is 1n its definite closed position. It will be observed that 'during the initial closing movement, the main contact 11 has been moved longitudinally. and tilted at the same time into the position shown in Fig. 2, by

reason of the fact that the insulated post 27 moves the contact 11 away from the con tact 10 durin the initial closing movement of the switc With the parts in their respective positions as shown in Fig. 2, if the push button 26 is released, the operating electroma et 25 will be deenergized and the bell cran operating member 23 will be permitted to rotate counter clockwise about the pivot 13 in accordance with its gravity bias. The insulated post 27 will be thus moved free from the main contact 11 and this contact will again tilt about the supporting pins 1 and 15, moving to the left into engagement with the contact 10 in accordance with the strain of the spring 18 which was set up during the initial closing movement of the main contacts 10 and 11. The arm 12 will be held in the position shown in Fig. 3

by meansof the holding electromagnet, so

that if there is an overload in the circuit, the current through the bucking bar 22 will be efiective to shift the flux of the holding electromagnet away from the armature 19 and thuspermit the arm 12 to return to its position as shown in Fig. 1, thus efl'ecting a very quick opening of the main contacts. The'bell crank operating member 23 is preferably of some non-magnetic material so that there will be no tendency for this arm to be held by the holding electromagnet.

The contacts 10 and 11 are preferably designed so as to permit a quick opening of the controlled circuit. The moment of inertia of the contact 10 is preferabl made uite small by having this contact re atively hght and by reducing as much as possible wthe weights of the armature 19 andthe arm 12. The contact 11, on the other hand, is preferably designed so as to have a relatively large moment of inertia, so that when the arm 12 begins its opening movement, the contact 11 will not immediately follow,

. thereby effecting a ary quick interruption of holding the controlled contacts in their.

closed positions'while there is an overload on the circuit such that these contacts should be permitted to automatically open.

desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by other means. What I claim as new and desire to secure by Letters Patent of the United States, is:

1. An electric switch comprising a pair of normally open independently movable cooperatin circuit controlling contacts, means for holding the first of said contacts in the closed position, an. operating member relatively movable with respect to both of said contacts and efiective by one movement thereof to move the first of said contacts toward the closed position and to move the second of said contacts away from the first contact, and means placed under a strain during said movement of said second contact for automatically moving the second of said contacts into engagement with the said first contact when said operating member is moved out of operative relation with both of said contacts.

2. An electric switch comprising a pair of normally open movablecooperating circuit controlling contacts, the first of said contacts being biased away from the second contact, means for biasing the second contact toward the first contact, an electromagnet for holding the first of said contacts in the closed position, and an operating member relatively movable with respect to said contacts and" having means for engaging both of said contacts to move the first of said contacts toward the closed position to be held by said holding means and simultaneously move the second of said contacts away from the said first contact while placing the said biasing means under strain, whereby upon the release of the operating memberv out of operative relation with the contacts the said second contact moves automatically in accordance with its bias into engagement with the first contact.

3. An electric switch comprising a pair of Y normally open independently movable coop.-

eratin circuit controlling contacts, the first of said contacts being biased away from the second contact, means for biasing thesecond contact toward the first contact, an electromagnet for holding the first of said contacts in the closed position, an operating member biased to one position and efiective by a forward movement thereof to move the first of said contacts to its respective closed position to be held by said holding means, and connections between said operating member and the said second contact for moving the second contact away from the first contact during the closing movement of the said first contact and placing the said biasing m under strain, whereby upon the release of said operating member the said second contact moves automatically into engagement with said first contact in response to the strain of said biasing means.

4. An electric switch comprising a pair of normally open movable cooperating circuit controlling contacts, means for holdin the first of said contacts in the closed position, supporting means for the second of said contacts arranged to efi'ect a tilting of the second contact when moved with reference to the first contact, an operating member for moving the first of said contacts to its closed position to be held by said holding means, connections between said operating member and the said second contact for moving the second contact away from the first contact, and means for moving the said second contact into engagement with the said first contact when said operating member is released. In witness whereof, I have hereunto set my hand this 5th day of December, 1924, JOHN F. TRITLE. 

